Pastimes: Gardening; Tree Planting at Home Helps a National Effort

By JACK STEINBERG, Special to The New York Times

Published: October 29, 1989

WASHINGTON, Oct. 28—
Home gardeners who have learned of the environmental threats posed by the greenhouse effect may not realize they can play a role in combating it.

The American Forestry Association, a citizens' conservation organization based here, says the nation can ease the threat of global warming by planting trees. The nonprofit group has launched a campaign, dubbed Global Releaf, which calls on Americans to plant 100 million trees in their cities and towns by 1992.

The plan is based on some basic facts of nature. Accumulation of carbon dioxide in the atmosphere is one of the chief causes of the greenhouse effect. Heat from the sun is trapped within the earth's atmosphere rather than radiated back into space. Trees can reduce the effects of global warming by absorbing carbon dioxide, that is storing carbon and releasing oxygen.

R. Neil Sampson, executive vice president of the forestry association, said planting trees in residential and urban areas would have two important environmental effects. The trees can reduce surplus carbon dioxide and, if planted strategically, can lower energy costs by shading buildings and streets from the heat of the sun.

''I think we're all aware this problem is very large,'' Mr. Sampson said. ''Here's one partial solution that lies at people's fingertips.''

Mr. Sampson and other experts agreed that there is no easy answer to the problem. They stressed, however, that a series of incremental steps might, with time, significantly reduce its effects.

If the organization reaches its goal of planting 100 million urban trees, scientists predict that by 2022, when the trees would be at medium growth, those trees would reduce carbon emissions by 10 million tons per year. The world currently burns an equivalent of 5 to 7 billion tons of carbon per year.

While Mr. Sampson and other experts acknowledged that the percentage of carbon dioxide absorbtion would be low, they agreed that every effort made, no matter how small, would help.

''If you set out to cure the greenhouse effect, forget it,'' Mr. Sampson said. ''But it's a step in the right direction and it's a step in how many people it involves in spreading the notion that human beings are part of the environmental solution.''

In light of the average number of trees planted each year, experts agree that the goal of an additional 100 million trees in urban and other business and residential areas seems reasonable.

According to the United States Forest Service, roughly 200 million trees are planted each year by private individuals and businesses who are outside of the forestry industry.

Ken Andrasko, a forestry analyst at the Environmental Protection Agency, is one of a number of experts applauding the tree planting campaign.

''The program is significant,'' Mr. Andrasko said, ''because it is the first vision of how a nation the size of the United States can deal with climate change. I think it's visionary in its reliance on urban forestry, a high degree of volunteerism and new ways of securing corporate involvement.''

Gregg Marland, a scientist at the Department of Energy's Oak Ridge National Laboratory, said he was impressed with the forestry association's emphasis on public participation in environmental concerns.

''I think it could be an important contribution,'' said Mr. Marland, one of the first scientists to advocate planting trees to stem global warming.

Mr. Sampson said home gardeners, who ''already have their hands in the soil,'' are an essential part of the program. He recommended that gardeners plant deciduous trees for shading on the southern or western sides of their homes or driveways.

Global Releaf, Mr. Sampson said, functions more as a ''national cheerleader'' than a sophisticated, multi-tiered organization.

''While it disseminates information about individual efforts and local programs, the forestry association can do little more than raise a small amount of money for interested groups that cannot afford their own trees,'' Mr. Sampson said.

The program relies on cities like Tuscon, Ariz., where local organizers have founded Tuscon Trees for Global Releaf.

Joan Lionetti, executive director of the local affiliate of Keep America Beautiful, said she was intrigued with Global Releaf and brought the idea to local university, government and community representatives.

The group recently included 160,000 Global Releaf brochures in the city's utility bills and is publicizing 20 officially registered nurseries and 10 trees that can be grown in the city's desert climate. The group hopes to plant 500,000 trees by 1996. ''It seemed to me like a wonderful way to give power to every man, woman and child in our community to make a difference in the environment,'' said Ms. Lionetti. ''We cannot keep up with the calls we are getting.''

For further information on the Global Releaf program or on organizing a local chapter, write to the American Forestry Association, P.O. Box 2000, Washington, D.C. 20013 or call (202) 667-3300.